ASSOCIATION BETWEEN BASAL GANGLIA HYPERPERFUSION AND CONTRALATERAL TONIC LIMB POSTURE DURING SEIZURES: ASSESSMENT USING SISCOM TECHNIQUE
Abstract number :
3.182
Submission category :
Year :
2002
Submission ID :
3550
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Elson L. So, Barbara Schauble, Terence J. O[ssquote]Brien, Robyn L. McClelland, Brian P. Mullan. Neurology, Mayo Clinic and Mayo Medical School, Rochester, MN; University of Melbourne, The Royal Melbourne Hospital, Parkville, Victoria, Australia; Nuclear
RATIONALE: Detailed analysis of ictal semiology provides important insights into the localization or lateralization of seizure focus and seizure propagation pathways. Our study was designed to identify subcortical distribution of SPECT hyperperfusion during seizures for correlation with clinical semiology. The SISCOM (Subtraction Ictal SPECT Co-registered on MRI) technique has the advantage of accurate delineation of subcortical structures for the localization of ictal SPECT hyperperfusion abnormalities (Neurology 1999;52;157-146).
METHODS: The study cohort consisted of patients with intractable partial epilepsy evaluated between July 1993 and July 1997. Patients were included in the study if they had ictal and interictal SPECT scans, and the video recording of the index seizure (i.e. during which either 99mTc-HMPAO or 99mTc-ECD was injected) was sufficient for assessment of seizure semiology. Blinded reviews of SISCOM images were conducted without knowledge of the clinical history, MRI imaging or video-EEG results. Video-EEG recording of the index seizure was reviewed to determine time of seizure onset and termination, duration of the seizure, and the presence of tonic limb posturing during the seizure.
RESULTS: Of the 68 subjects, 39 (57.4%) were males and 29 (42.6%) were females. The average age at time of study was 31.4 years (range 1.5 [ndash] 61), and the average duration of epilepsy was 19 years. Right basal ganglia hyperperfusion was significantly associated with left tonic limb posturing. 54.6% (6/11) of the patients with right basal ganglia hyperperfusion had left tonic posturing during the seizure, versus only 21.1% (12/57) of those without right basal ganglia hyperperfusion (p=0.021). However, left basal ganglia hyperperfusion was not associated with right tonic posturing (p[gt]0.05). There is a tendency for right basal ganglia hyperperfusion to be associated with longer latency from seizure onset to appearance of contralateral tonic limb posture (p=0.07). Unilateral basal ganglia hyperperfusion on either side was not significantly associated with ipsilateral tonic posturing (p[gt]0.05).
CONCLUSIONS: Using SISCOM image analysis, our finding of association between ictal basal ganglia hyperperfusion and contralateral tonic limb posture is similar to that previously reported for dystonic limb posture using visual inspection of SPECT scans. (Neurology 1992;42:371[ndash]377). However, the ability to detect the association between basal ganglia hyperperfusion and tonic limb posture may potentially be influenced by factors such as the timing of the posturing.
[Supported by: Mayo Foundation for Research and Education]